注入訊號強度對除頻器相位雜訊影響之研究

The Study of Injection Strength onto the Phase Noise of Frequency Divider

董洛均(Lo-Chun Tung)

指導教授 ： 吳建華

國立中正大學/工學院/電機工程學系/碩士(2014年)

摘要

此論文為射頻收發機系統中，頻率合成器所需之注入鎖定振盪器。使用台積電1P6M 0.18μm CMOS和3P6M 0.18μm BiCMOS兩種製程設計。
高頻除頻器在通常是接在振盪器之後，使頻率降低。此本論文提出三個應用在K頻段的除頻器，其中兩個為除四除頻器及一個除六除頻器。本論文提出使用混波方式產生電流強度較高的諧波項再去作混頻，因電流強度較強而提升鎖頻範圍，運用簡單架構提升了注入效率，並保有低的功率消耗。
第一個除四除頻器使用雙推式振盪器方式，產生電流強度較高的諧波項，再與注入訊號混頻，增強了電流強度因而提升鎖頻範圍，並保有低的功率消耗。鎖頻範圍由19.2 GHz至22.3 GHz。偏壓為1.2V，功率消耗為4.32 mW。
另一除四除頻器，除了基本直接注入除四電路產生的注入電流，另外使用基極注入，新增兩條注入電流，增強注入電流強度，達到低功耗且高鎖頻範圍的目的。本架構和傳統直接注入除四電路相比，增加80%的鎖頻範圍。鎖頻範圍由18.8 GHz至24.4 GHz。偏壓為1.2V，功率消耗為4.42 mW。
除六除頻器運用混頻方式來克服高除數消耗功率較高的缺點。鎖頻範圍由15.35 GHz至21.49 GHz。偏壓為1.2V，功率消耗為6.43 mW。
同時探討，提升電流強度對注入鎖定除頻器的相位雜訊變化。及探討相對於注入訊號的相位雜訊與電路本身的相位雜訊何時會有20log(n)的差異。量測數據證實了注入鎖定時的相位雜訊，與除頻器未注入訊號時的相位雜訊及訊號源本身相位雜訊之間的關係。

關鍵字

交互轉合對 ； 相位雜訊 ； 鎖頻範圍 ； 除頻電路

並列摘要

The study of this thesis focuses on the design of injection-locked oscillator used in the phase lock loop of the wireless transceiver. All the proposed circuits were implemented by TSMC 0.18μm 1P6M CMOS and 0.18μm 3P6M BiCMOS process.
In this thesis, two divide-by-four frequency dividers are proposed for K-band application and one divide-by-six frequency dividers is proposed for. Based on the formulation of locking range, the enhancement of injection signal will make the locking range wider. Following this concept, this thesis demonstrates wide-locking frequency dinider by the mixing technique and body injection topology to produce stronger injection current.
In chapter II, a divide-by-four frequency divider with push-push oscillator is demonstrated. Locking range of the proposed ILFD is enhanced by mixing the injection signal and the second harmonic from push-push oscillator. By this method, the weakness of direct injection frequency divider by four with weak high order harmonic signal can be overcome. The measured locking range is from 19.2 GHz to 22.3 GHz (15%) with an injection power of 0dBm. The measured maximum output power is -0.19dBm with a tuning voltage of 2V. The power consumption of the core circuit takes 4.32mW from a 1.2V power supply.
In chapter III, a direct injection frequency divider by four with body injection is demonstrated. Based on direct injection, a second harmonic signal and input signal are injected to the body of direct injection transistor at the same time. The locking range can be intensified significantly by this technique. The measured locking range is from 18.8 GHz to 24.4 GHz (26.3%) with an injection power of 0dBm. The measured maximum output power is -1.84dBm with a tuning voltage of 2V. The power consumption of the core circuit takes 4.42mW from a 1.2V power supply.
In chapter IV, a high output power frequency divider by six is proposed. The application of high order ILFD is mentioned in Section 6.1. The proposed topology realizes divide-by-six mechanism by employing the second and third harmonic signal instead of fifth order harmonic signal. The injection current is enhanced with this method and locking range is also increased. The measured locking range is from 15.3 GHz to 21.59 GHz (33.3%) with an injection power of 0dBm. The measured maximum output power is -1.07dBm with a tuning voltage of 2V. The power consumption of the core circuit takes 6.43mW from a 1.2V power supply.
Furthermore, phase noise with respect to the external injection signal is discussed and the formula is presented in Section 2.5. The relationship between locking range, injection power, frequency offset is clarified by the measured results.

並列關鍵字

phase Noise ； Locking range ； Frequency divider ； cross-couple pair

參考文獻

[1] Takayuki Shibasaki, Hirotaka Tamura, Kouichi Kanda, Hisakatsu Yamaguchi,

Junji Ogawa and Tadahiro Kuroda “20-GHz Quadrature Injection-Locked LC Dividers With Enhanced Locking Range,” IEEE J. Solid-State Circuits, vol. 43, no. 3, pp. 610-618, Mar. 2008.

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[4] Xiangdong Zhang ,Xuesong Zhou, and Afshin S.Daryoush, “A Theoretical and Experimental Study of the Noise Behavior of Subharmonically Injection Locked Local Oscillators,” IEEE Trans. Microwave Theory Tech., vol. 40, pp. 895-902, 1992.